title: Intraluminal gel ultrasound and eco-color doppler: new tools for the study of colorectal cancer in mice.
abstract: OBJECTIVE
  Azoxymethane (AOM) is a potent carcinogen that induces colorectal cancer in mice. Intraluminal gel ultrasound is a technique based on the injection of gel into the rectum. This technique allows the colon to be straightened and to visualize and identify tumours.
  
  
  METHODS
  Twenty female C57Bl/6J mice were injected intraperitoneally with 10 mg/kg of AOM one time per week for six weeks. The mice were monitored by ultrasound with a Vevo 2100 system. We evaluated the tumour area and tumour vasculature with Ecocolor-Doppler (ECD). Histological examination of sacrificed mice was employed as the standard protocol.
  
  
  RESULTS
  After 40 weeks from the injection, ultrasound analysis revealed the presence of tumours in 50% of all mice. Ex vivo analysis revealed the presence of 57% true-positives and only one false-positive. In two mice, ultrasound did not reveale the presence of tumour due to its small dimension. This indicates that ultrasound is able to detect only tumours with sizes ≥3 mm².
  
  
  CONCLUSIONS
  Ultrasound is a rapid examination compared to other diagnostic techniques. It has a good sensitivity when the tumours reach the dimensions of 3 mm² or more. Intraluminal gel allows for the tumour area to be evaluated when mice are still alive, while ECD allows for vasculature of intestinal walls and colorectal tumour to be evaluated.
authors.affiliation: Animal Facility, Istituto Nazionale per lo Studio e la Cura dei Tumori Fondazione Giovanni Pascale, IRCCS, Naples, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Barbieri
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Barretta
authors.forename: Domenica
authors.initials: D
authors.lastname: Rea
authors.forename: Carmine
authors.initials: C
authors.lastname: Picone
authors.forename: Olimpia
authors.initials: O
authors.lastname: Fabozzi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Palma
authors.forename: Luciano
authors.initials: L
authors.lastname: Antonio
authors.forename: Alessandro
authors.initials: A
authors.lastname: Federico
authors.forename: Sabrina
authors.initials: S
authors.lastname: Bimonte
authors.forename: Francesca
authors.initials: F
authors.lastname: Setola
authors.forename: Elisabetta
authors.initials: E
authors.lastname: De Lutio Di Castelguidone
authors.forename: Maria
authors.initials: M
authors.lastname: Castellano
authors.forename: Adolfo Gallipoli
authors.initials: AG
authors.lastname: D'Errico
authors.forename: Michele
authors.initials: M
authors.lastname: Caraglia
authors.forename: Claudio
authors.initials: C
authors.lastname: Arra
mesh_terms: D000818:Animals; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color / Q000379:methods
keywords: Ultrasound; colorectal cancer; mouse model